This application describes the Chinese Clinical Trials Unit on HIV Research (CCTU) and its capacity to serve as a Clinical Trials Unit (CTU) for the NIAID clinical research networks. Though widely noted for the rapid scale up and success of HIV treatment and prevention services, China faces ongoing public health challenges surrounding HIV. Its unique epidemic profile offers opportunities to examine the following research topics: - As part of the HIV Prevention Trials Network (HPTN), assess the 1) acceptability and feasibility of early antiretroviral treatment as a prevention strategy in HIV serodiscordant couples, 2) feasibility and efficacy of an enhanced test, link, and care strategy to reduce HIV transmission in urban MSM and to improve STI treatment uptake in FSW, and 3) acceptability and adherence to approved PrEP regimens among MSM in China; - As part of the HIV Vaccine Trials Network (HVTN), evaluate 1) the safety and efficacy of poxvirus-protein combination vaccine candidates among high HIV-incidence risk groups, 2) specifically evaluate safety and efficacy of prime-boost vaccine strategies utilizing the Chinese-developed vaccinia plasmid vector rTV and collaborator protein candidates, and 3) assess the feasibility, safety, and efficacy of combined vaccine and PrEP approaches; - As part of the AIDS Clinical Trials Group (ACTG), to investigate 1) optimal regimens, timing, and efficacy of new drugs for HIV/Hepatitis co-infection as well as their interaction with HAART drugs, and 2) efficacy of integrated strategies to prevent and treat co-morbidities, including TB, diabetes, and other noncommunicable co-morbidities in diverse patients, including elderly patients. CCTU will consist of up to 6 Clinical Research Sites (CRSs), which represent the diverse range China's at-risk and patient population structures and viral diversity. The outcomes of CCTU's research will be widely applicable to national, regional, and global efforts on HIV/AIDS prevention and control.